What is Superior Limbic Keratoconjunctivitis?
Superior limbic keratoconjunctivitis (SLK) is an inflammatory condition that affects the upper area of the cornea and conjunctiva. Superior limbic keratoconjunctivitis is highly associated with thyroid disease, but it may also be caused by dry eye or contact lens irritation. Symptoms of superior limbic keratoconjunctivitis are redness (especially of the upper portion of the conjunctiva), eye pain, and feeling like something is stuck inside of the eye. Treatment of superior limbic keratoconjunctivitis involves antibiotic drops and anti-inflammation drops/.
- Superior limbic keratoconjunctivitis is an inflammatory disorder that affects the superior cornea and conjunctiva.
- Superior limbic keratoconjunctivitis is highly associated with thyroid disease.
- Symptoms of superior limbic keratoconjunctivitis include redness, painful foreign body sensation, watery eyes, and light sensitivity.
Understanding Superior Limbic Keratoconjunctivitis
Superior limbic keratoconjunctivitis causes inflammation of the superior areas of the cornea and bulbar conjunctiva of the eye. It may be difficult to see this region of the eye unless you look down and pull up the upper eyelid. The cornea is the clear, dome-shaped outer coating of the eye. The bulbar conjunctiva is the clear lining over the white part of the eye. In superior limbic keratoconjunctivitis, the superior (top) area of the cornea and conjunctiva is affected. Inflammation causes the upper part of the bulbar conjunctiva, which is usually white, to look red and inflamed. The rest of the conjunctiva is relatively white and unaffected.
Superior limbic keratoconjunctivitis predominantly affects middle-aged women between 30 to 60 years old. Although it usually affects both eyes, it may affect one eye more than the other. Approximately 30% to 50% of all people diagnosed with superior limbic keratoconjunctivitis have hyperthyroidism. Therefore, if your eye doctor detects superior limbic keratoconjunctivitis, they will most likely order further lab testing to determine if you have thyroid disease.
Symptoms of superior limbic keratoconjunctivitis include:
- Feeling like there are rocks underneath the upper eyelid
- Sensation of something stuck inside of the eye
- Eye pain
- Light sensitivity
- Watering or tearing of the eyes
- Excessive blinking
When evaluating the eyes for superior limbic keratoconjunctivitis, the doctor checks for various signs that indicate the presence of inflammation. Signs of superior limbic keratoconjunctivitis include:
- Redness located on the superior bulbar conjunctiva
- Engorgement of the blood vessels in the conjunctiva
- Papillae (tiny bumps) located on the inside of the upper eyelid
- Extra folds of bulbar conjunctiva
- Staining of bulbar conjunctiva with Rose bengal dye
Testing for superior limbic keratoconjunctivitis include:
- Slit lamp analysis: The eye tissues are assessed for redness and inflammation under the microscope.
- Rose Bengal dye: A pink dye is dabbed onto the front part of the eye, and it stains the area of inflammation pink.
- Other thyroid eye disease Tests: : Additional testing may be performed to evaluate if there is bulging of the eyes, decreased motility of the eye muscles, or dryness of the inferior cornea. These are other eye-related complications of thyroid disease.
- Lab work for thyroid disease: The eye doctor may order tests for thyroid function including T3, T4, and TSH.
Thyroid disease occurs when the thyroid gland produces too much hormone (hyperthyroidism) or too little hormone (hypothyroidism). The thyroid gland is located at the front of the throat and produces hormones that regulate metabolism. Upto 50% of people diagnosed with superior limbic keratoconjunctivitis also have hyperthyroidism. Other systemic symptoms of hyperthyroidism include rapid heartbeat, anxiety, weight loss, increased appetite, sweating, and heat intolerance.
Graves Disease is a form of hyperthyroidism due to overactivity of the thyroid gland. Graves Disease can affect the eyes by causing:
- A ‘stare’ appearance due to eyelid retraction
- Bulging of the eyes (exophthalmos)
- Decreased eye muscle movement
- Double vision
- Eye pain
- Optic nerve compression
The treatment available for superior limbic keratoconjunctivitis varies based on the severity of inflammation. If the inflammation is mild, it can be treated with artificial tears. For moderate or severe cases, antibiotic drops and anti-inflammation drops are used. Some examples of anti-inflammation drops include: steroids, tacrolimus, vitamin A and cyclosporine. In rare cases, surgery may be required.